Regulating the product quality of COVID-19 antigen testing reagents: A tripartite evolutionary game analysis under China's legal framework

Personal purchases of novel coronavirus antigen detection reagents (ADRs) for self-detection have contributed to the optimization of medical resources and containment of the COVID-19 pandemic. The recurring occurrence of false testing results in China has generated concerns regarding the quality of ADRs and the testing mechanism for medical devices. Academic viewpoints and remarks on the sensitivity, application possibilities, and product innovation of ADRs may be found in the extant scientific literature. However, the current research does not explore the microscopic product quality concerns that emerge throughout the production and marketing of ADRs. To explore strategic equilibrium circumstances and behavioral evolution processes, an evolutionary game model was developed to include ADR manufacturers, third-party medical device inspection agencies, and regulatory authorities. The results reveal that the quantity of illegal incentives, the cost of regulation, and the loss of government credibility have a major impact on the decisions of regulatory authorities and determine three potential systemic equilibrium states. To maximize social welfare, ADRs should be incorporated into China's medication price monitoring system in order to manage market prices. To cut regulatory expenses, the government should employ blockchain technology for traceable network regulation of ADR product quality. The government should also protect the people's right to free speech and encourage online reporting of adverse incidents caused by ADRs. The conclusions of this article can provide many developing nations with important insights for regulating the quality of ADR products.

A New iNKT-Cell Agonist-Adjuvanted SARS-CoV-2 Subunit Vaccine Elicits Robust Neutralizing Antibody Responses.

Adjuvants are essential components of vaccines. Invariant natural killer T (iNKT) cells are a distinct subset of T cells that function to bridge the innate and adaptive immunities and are capable of mediating strong and rapid responses to a range of diseases, including cancer and infectious disease. An increasing amount of evidence suggests that iNKT cells can help fight viral infection. In particular, iNKT-secreting IL-4 is a key mediator of humoral immunity and has a positive correlation with the levels of neutralizing antibodies. As iNKT cell agonists, αGC glycolipid (α-galactosylceramide, or KRN7000) and its analogues as vaccine adjuvants have begun to provide vaccinologists with a new toolset. Herein we found that a new iNKT-cell agonist αGC-CPOEt elicited a strong cytokine response with increased IL-4 production. Remarkably, after three immunizations, SARS-CoV-2 RBD-Fc adjuvanted by αGC-CPOEt evoked robust neutralizing antibody responses that were about 5.5-fold more than those induced by αGC/RBD-Fc and 25-fold greater than those induced by unadjuvanted RBD-Fc. These findings imply that αGC-CPOEt could be investigated further as a new COVID-19 vaccine adjuvant to prevent current and future infectious disease outbreaks.

Potent Neutralizing Antibodies Elicited by RBD-Fc-Based COVID-19 Vaccine Candidate Adjuvanted by the Th2-Skewing iNKT Cell Agonist.

The development of a safe and effective COVID-19 vaccine is of paramount importance to terminate the current pandemic. An adjuvant is crucial for improving the efficacy of the subunit COVID19 vaccine. α-Galactosylceramide (αGC) is a classical iNKT cell agonist which causes the rapid production of Th1- and Th2-associated cytokines; we, therefore, expect that the Th1- or Th2-skewing analogues of αGC can better enhance the immunogenicity of the receptor-binding domain in the spike protein of SARS-CoV-2 fused with the Fc region of human IgG (RBD-Fc). Herein, we developed a universal synthetic route to the Th1-biasing (α-C-GC) and Th2-biasing (OCH and C20:2) analogues. Immunization of mice demonstrated that αGC-adjuvanted RBD-Fc elicited a more potent humoral response than that observed with Alum and enabled the sparing of antigens. Remarkably, at a low dose of the RBD-Fc protein (2 µg), the Th2-biasing agonist C20:2 induced a significantly higher titer of the neutralizing antibody than that of Alum.